An internal combustion engine of a vehicle may be automatically stopped during conditions when vehicle speed is less than a threshold and when a driver demand torque is less than a threshold. The engine may be automatically stopped while the vehicle is decelerating or after the vehicle has come to a complete stop. During automatic engine stop, delivery of fuel to the engine may cease and engine rotation may stop. By ceasing combustion and stopping the engine, it may be possible to conserve fuel and extend driving range of a vehicle. However, if the vehicle's engine stops more frequently than is desired, the vehicle's fuel economy may be reduced and vehicle engine starting components may degrade at an accelerated rate.
The inventor herein has recognized the above-mentioned issues and has developed a vehicle operating method, comprising: receiving vehicle road position data of a first vehicle and a second vehicle to a controller; adjusting a relationship between accelerator pedal position and driveline torque of the first vehicle in response to a distance between the first vehicle and the second vehicle; and adjusting output of a driveline responsive to the relationship.
By adjusting a relationship between accelerator pedal position and driveline torque output in response to a distance in between a first vehicle and a second vehicle, it may be possible to provide the technical result of improving vehicle fuel economy and improving whether or not to automatically stop an engine of a driveline. For example, if a distance between a first vehicle and a second vehicle is greater than a threshold distance, a driveline may generate a first torque that is greater than a second torque when a human vehicle driver applies an accelerator pedal to a first position. However, the driveline may generate the second torque that is less than the first torque when the human vehicle driver applies the accelerator pedal to the first position when the distance between the first vehicle and the second vehicle is less than the first threshold. The lower second torque may help to reduce vehicle acceleration at times when the vehicle may have to stop shortly after the acceleration begins. In addition, by lowering the vehicle acceleration for a given accelerator pedal position, an engine of the vehicle may stop less frequently at times when the vehicle may restart shortly after stopping.
The present description may provide several advantages. Specifically, the approach may improve vehicle fuel economy by lowering vehicle acceleration rates and engine torque output for a given accelerator pedal position at times when the vehicle may stop shortly after the vehicle begins to accelerate. Further, the approach may help to avoid engine stopping when the engine will be restarted shortly after being stopped, thereby avoiding engine stoppages that may not improve vehicle fuel efficiency. In addition, the approach may reduce degradation of engine starting components by reducing less beneficial engine stoppages.
The above advantages and other advantages, and features of the present description will be readily apparent from the following Detailed Description when taken alone or in connection with the accompanying drawings.
It should be understood that the summary above is provided to introduce in simplified form a selection of concepts that are further described in the detailed description. It is not meant to identify key or essential features of the claimed subject matter, the scope of which is defined uniquely by the claims that follow the detailed description. Furthermore, the claimed subject matter is not limited to implementations that solve any disadvantages noted above or in any part of this disclosure.